77 280z with N47 head, stock engine, should I remove exhaust port inserts? Does it help?

[Obie 280Z]

Anyone have any experience with removing the inserts in the exhaust ports? Putting new ceramic coated headers on and wondered if taking them out, not sure how easy it would be w/o the head off, would improve flow? Thanks in advance.

 

 

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[Zed Head]

If you measure the area of the port without the liners you'll probably find that you'd have to do a lot of extra work to get the header opening to match the head.  If the header opening is smaller than the head opening you'll get turbulence that will ruin flow.  Beside that, without a lot of other head work, enlarging the exhaust port is probably pointless.  Somebody over on Hybridz showed that there's very little gain in flow from removing the liners. 

They're cast in.  Some grinding on certain areas will get them to fall out, sometimes they fall out on their own.  Once they're out you'll have a rough casting that needs smoothing.

 

[Obie 280Z]

Thanks Z head, you helped me make the decision to leave them in. They all are firmly attached. Last question, anti seize on the new stud going into the head or not? Thanks


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[siteunseen]

I've always used it there, after reading steel into aluminum needs it.

Read applications, automobiles   https://www.permatex.com/products/lubricants/specialty-lubricants-anti-seize/permatex-anti-seize-lubricant-2/

Automobile

Suggested Applications: For easy removal of spark plugs, cylinder head and exhaust head bolts; apply to anchor pins on brake assemblies, u-bolts and spring bolts, hinges, gears, chain, sprockets and rollers.